Disputed study claims Betelgeuse is much closer to supernova

Tohoku University astronomers claim that “the core will collapse in a few tens years after the carbon exhaustion.”

These scientist on planet Earth conclude that I'm "in the late stage of core carbon burning, and a good candidate for the next Galactic supernova". As if I didn't know that myself...https://t.co/JXWR23fU0H

— Betelgeuse Status (@betelbot) June 2, 2023

The key to its explosion lies within the fuel it relies upon.

The element fueling the star holds the ability to forecast its eventual explosion as a supernova.

This is difficult for scientists to assess since they cannot see through the core of the star, where such fusion reactions occur. 

In the latest study, which is uploaded on a pre-print server, the team stated: “Betelgeuse is in the late stage of core carbon burning, and a good candidate for the next Galactic supernova.”

Throughout its billions of years of existence, the red giant star has fused most of its hydrogen into helium. This study indicates that Betelgeuse has progressed beyond the stage where our Sun is and is no longer converting hydrogen into helium in its core. 

Following this major sequence is the usage of carbon as a fuel source from its cores. 

Not many experts agree with the results 

However, the carbon-burning cycle is divided into many stages. As a result, predicting when Betelgeuse will go supernova is dependent on which of those carbon phases it is in. Unfortunately, at present, there is no conclusive evidence available regarding the star's current position within these carbon phases.

"In fact, it is not possible to determine the exact evolutionary stage, because surface conditions hardly change in the late stage close to the carbon exhaustion and beyond," the researchers write. 

Recent reports of my imminent demise are indeed a bit premature, @chrislintott https://t.co/tCS0hmMDCG

— Betelgeuse Status (@betelbot) June 7, 2023

This implies that astronomers have no idea about the chemistry cooking up in the core of the star. 

As per reports, some experts disagree that Betelgeuse is in its last stages. And they suspect that the star is still dependent on helium as a fuel. 

The new work is derived from observations as well as computational models based on the star pulse cycles (brightness and dimness phases).

This neighboring star, 642 light-years from Earth, is our best chance to witness a supernova, yet it persistently refuses to explode.

The study has been accepted for publication in the journal Monthly Notices of the Royal Astronomy Society.

Study Abstract:

Betelgeuse is a well-known bright red supergiant that shows semi-regular variations with four approximate periods of 2200, 420, 230, and 185 days. While the longest period was customarily regarded as LSP (long secondary period) of unknown origin, we identify the ~2200-d period as the radial fundamental mode, and the three shorter periods as the radial first, second, and third overtones. From a nonadiabatic pulsation analysis including the pulsation/convection coupling, we have found that these radial pulsation modes are all excited in the envelope of a model in a late stage of the core-carbon burning. Models with similar pulsation property have masses around 11M_\odot (19M_\odot at ZAMS) with luminosities (log L/L_\odot =5.27~5.28) and effective temperatures (log T_{eff}\approx 3.53) that are consistent with the range of the observational determinations. We also find that a synthetic light curve obtained by adding the fundamental and the first-overtone mode qualitatively agrees with the light curve of Betelgeuse up to the Great Dimming. We conclude that Betelgeuse is in the late stage of core carbon burning, and a good candidate for the next Galactic supernova.